Signaling system for railroads



May 14, 1940. J. E. WILLING SIGNALING SYSTEM FOR RAILROADS Original Filed Feb. 17, 1932 ATTORNEY 8 [8 m qwmm e 2, +8 I 02 n B TSY: mm 5 8 mvfiv mw u u 3 E 3 3N u I ||J||||L #2 .3 132% a \h 2 m m F L m m i E m m m v m P m s m w n F LHT 11% F IIIII a A NH w H Q wm u Patented May 14, 1940 UNITED STATES PATENT OFFICE SIGNALING SYSTEM FOR RAILROADS Joseph E. Willing, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

1 Claim.

This invention relates to absolute-permissiveblock signaling systems for railroads, and more particularly to such a system employing direct current polarized home-distant relays of an im- .1 proved type.

The present application is a division of my prior application Ser. No. 593,549, filed February 17, 1932, for Signaling system for railroads, now Patent 2,072,232, granted March 2, 1937.

10 An absolute-permissive-block signaling system is a system in which a single track section is signaled for trafiic moving in either direction, and a system which affords the same protection and facility for trains following each other through the single track section as is afforded in modern signaling systems for tracks signaled for one direction of traffic only, and in which an opposing train is prevented from entering a single track section already occupied by a train or trains. This facility of train signaling is accomplished by connecting the various home-distant relays for eachdirection of travel intumble-downor repeater fashion, so that the deenergization of one relay causes the next relay in the rear to be deener- 25 gized, and so on through the entire track section, and. in which a directional relay, such as a stick relay, is employed for closing an auxiliary circuit to the next home-distant relay in the rear of a signal at stop, completed in response to the movement of a train in the proper direction.

In signaling systems of the type mentioned, the home-distant relay should be slow to pick up, in order to prevent the false or improper picking up of a directional stick relay, and such home- 35 distant relay should be slow to drop, so that the directional stick relay can be picked up under certain traffic conditions.

In accordance with the present invention it is proposed to use a polar neutral relay, as such 40 home-distant relay, wherein a short circuited winding 60 of low resistance or usual copper bank is provided for making the relay slow to release its neutral armature.

It is further proposed to include a resistance in 5 series with the main winding of such home-distant relay, which resistance is short-circuited when the relay assumes its attracted position, in order to render such relay slow to pick up, but after being picked up, saturates the main mag- 50 netic circuit so as to induce a heavy current in the short circuited winding, to make it slow dropping.

Another function performed by home-distant relays of this type is that upon pole changing of 55 the main circuit for the relay, the neutral armature of such relay will be only momentarily deenergized whereby the slow action of subsequent horne-distant relays prevents what is known in signal parlance as a kick-off, which consists in momentary sequential deenergization of a series of home relays, this by reason of momentary deenergization of the first of these relays due to pole changing of its energizing circuit.

Other objects, purposes and characteristic features of the present invention will in part be obvious from the accompanying drawing and will in part be more fully described hereinafter.

In describing the invention in detail reference will be made to the accompanying drawing, which shows one embodiment of the invention applied to a portion of a single track section of a rail- Way.

Referring to the drawing, the track rails l have been shown divided into blocks by insulating joints 2, of which the block I and the adjacent ends of two other blocks H and J only have been shown, and in which each block is further divided by insulating joints 3 to constitute a divided block having two track circuited sections each provided with a track circuit including a battery B (containing a suitable exponent) and a track relay T (containing a suitable exponent). At the entrance end to each block, for each direction of traffic, has been shown a light signal S (containing a proper exponent) of which the east-bound signals have been designated S and S and the west-bound signals have been designated S and S Since each of these signals is controlled in ex actly the same way it will suffice to describe the control circuits for the signal 8*, like parts for controlling other signals being designated by reference characters having distinctive exponents. The signal S is controlled by home-distant relay HD and a track relay T a back contact of the directional stick relay 5S being included in the energizing circuit for the home-distant relay HD for checking purposes. The home-distant relays for the signals S and S and the associated circuits have for convenience been omitted but are the same as those of S and S respectively. It is believed that the invention is most readily understood by considering the operation of the system as effected by the movement of trains.

Operation Under normal clear traific conditions, the home-distant relay HD is energized through the following circuit:beginning at the terminal (B+) of a suitable battery having its mid-point connected to the common return wire C, front contact it of relay HD wires H and back contact I l of the stick relay BS, wire l5, front contact 56 of the track relay T wire l'l, back contact it of the opposing directional stick relay wire 19, front contact of the track relay T wire Ill, main winding of the relay HD wire 22, resistance unit R wires 23, Eli, C, 25 and 25 t0 the mid-point of said battery.

Let us first assume that a West-bound train,- that is a train moving from right to left, is entering the block J. The entrance of this train will result in opening of the contact ltl (not shown) of the track relay T (not shown) thereby deenergizing the home-distant relay HD Drop ping of the home-distant relay i-lD will result in opening of its contact I'll, thereby illuminating the danger aspect of signal S by lighting of the red lamp R. Further, opening of the contact ii] of the relay HD will break the energizing circuit for the home-distant relay HD heretofore traced, and this relay H13 will in the same way deenergize the relay HD (not shown) in the rear thereof. This sequential deenergization of the home relays I-ID, H13 etc., is known as the tur ble-down function, which blocks opposing trains, and prevents their entering a single track section already occupied by the train.

As the train in question passes the signals S and 6 these signals will indicate tra conditions in advance, and will indicate trainc conditions to other following trains, all in a man er as will be described hereinafter in connection. th the operation of signals S and S Let us now assume that an east-bound train, moving from left to right enters the block The entering of this train into the block T will result in tumbling down of the home re s for the signals S and S so that these signals S and S will assume their stop condition. As soon as this train in the block I-I passes into the second track circuit thereof containing the track relay T it will cause dropping of this track relay T and opening of its contact it". At th time, assuming the existence of clear trafiic concitions in advance for east-bound trains, there is com-- pleted the following energizing circuit for the green lamp G: beginning at the terminal (3+) of a suitable battery, front contact l l or the relay HD wires ii and 52, polar contact 3t assuming its right-hand position, wire green lainp G of the signal S to the common return Wire C connected to the mid-point of said battery.

Let us now assume that the train in question passes the signal S In so doing it eilects deenergization of the track relay T Dropping of contact Ell of the track relay '1' breaks the energizing circuit for the relay H13 but the rapid dying of flux in the main core structure of the relay HD causes a voltage to be induced in the or" this relay, th

secondary winding or slug to by causing current to flow therein and hold H13 up for a short time, and since the relays arc built to be quick acting, this period or" tine icontact will close the following stick circuit: beginning at the terminal (13+) of the local battery, back contact 38 of the track relay T wires and stick contact of the relay 48, wires and winding of the relay 48 to the common return wire C. Immediately upon dropping of the relay H33 an auxiliary stick circuit for the relay is closed, which may readily be traced, and includes the back contact 43 of the relay E33 and the stick contact of the relay 455.

As soon the cast-bound train has passed entirely out of the block H, the contact W of the track relay T will be closed, thereby closing a ca non circuit for the next hoine-distant relay in the rear, this caution circuit leading from the terminal (B through front contact M of the stick rel y wire it", front contact 16 of the track relay T wire ll back contact E8 of the stick relay line wire if), etc.

Let us now assume that the east-bound train p through the block I and enters nis train will of course, assuming dvance to be favorable, find the signal S energized when as this signal 8, all in a manner as east-bound train enters the block track relay T it will pick the ecticnal stick relay fiS, in a manner as ady pointed out in connection with the direlay 1S.

s the rear end of the train passes entirely out of the b-locl I, the home-distant relay HD which was deene during the entire occupancy of the block is now energized to its left-hand position through the following caution circuit: begin lg at the t nnal (B), front contact Id of he directional stick relay GS, wire l5, front contact oithe track relay T wire ll, back contact E8 of the stick relay 53, wire l9, front contact 2% of the track relay 1?, wire '2 l, winding of the relay H'D wire 82, resistance unit R wires 3.3, 2 5, 2515, C, "H and 26 to the mid-point of the battery. The closure of the circuit just traced will operate the relay Ell) to its left-hand clotted position, tiereby placing the polar contact til in a position to energize the caution lamp Y, instead of the green lamp G, thereby informing an approaching train that there is a train in the second block in advance, namely in the block J. Let us now assume that the train in question, which is now occupying the block J, passes entirely out of this block J. For reasons already explained the horns-distant relay lh'D will now be energized by current of negative polarity, and thus will move its neutral contact 33 to its at tracted position, thereby breaking the stick circuit for the directional stick relay 65, resulting in this relay i-ES being deenergized and dropping its contact l as a result of which the normal circuit for the home-distant relay HD is again complete, resulting in the application of current of 'v polarity, instead oi": current of negative polarity, to the relay PD". As the train in question now passes beyond the second blocl: in advance of the signal :5, this signal S will be returned to its normal clear position for reasons mentioned in connection with the signal 5 so that the signal system will again assume its normal condition, as shown in the drawing.

Attention. is now directed to the resistance unit R included in series with the relay HD It will be noted that this resistance unit is normally short-circuited through a front contact 50 of the home-distant relay HD*. The purpose of this Fed in connection with the signal fi l resistance R is to increase the time necessary for the relay HD to assume its neutral armature at-- tracted position. The advantage in having this home-distant relay I-ID slow in picking up may be best explained by assuming a short train moving at high speed from right to left in the block I. As this train passes over the insulating joints 3, and if the track relay T is slow to drop, as a shunted track relay is, and the track relay T is quick to pick up as is usually the case, the home-distant relay H13 will be momentarily energized during this rapid passage of a short train over the insulating joints 3, but the provision of the resistance R which is now included in series with the relay I-ID, the contact 58 being open, prevents the relay I-ID from momentarily picking up, it being understood that momentary picking up of the relay E3 with the later deenergizing of the track relay T might pick up the stick relay 48 at a time when the directional stick relay 48 should not pick up to energize HD (not shown) to put signal S (not shown) to caution, to thus allow an east-bound train, to run into the West-bound trains. In applicants construction, however, the relay ED is sufiiciently slow to pick up to prevent such false picking up of the stick relay.

Applicant has thus proposed a system of single track signaling of the absolute-permissive-block type, which employs polar neutral relays which by their construction will not drop on momentary deenergization, and hence pole-changing, as of I-ID will not drop HD etc., and these relays have been provided with an auxiliary resistance R which causes these relays to be slow to pick up as is required in an absolute-permissive-block signaling system, thereby preventing accidental picking up of the opposing stick relay, and the slow dropping function obtained is taken advantage of to afiord picking up of the associated stick relay, all in a manner as already pointed out in the foregoing description, so that a comparatively simple system of absolute-permissive block signaling employing a comparatively few relays, has been provided.

The above rather specific description of one form of the invention, has been given solely by Way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, this invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, are intended to be included by this invention, as come within the scope of the appended claim.

Having described my invention, I now claim:

In combination, a relay having slow pick up and slow release characteristics and including an armature, a magnetic core and an operating winding on the core, an external resistance separate from the winding and connected in series with the winding to thereby produce slow pick up characteristics in the relay, means separate from the winding and positioned on the core and constituting a low resistance short-circuited loop to produce slow release characteristics in the relay, and circuit means closing a relatively low resistance shunt across the external resistance only upon the relay having picked up its arma ture, whereby the relay pick up current is less than the relay holding current, and the functioning of the said loop in producing slow release characteristics in the relay is unaffected by the said external resistance.

JOSEPH E. WILLING. 

